Hello Phil - thanks for giving me an explanation of the difficulties in implementing ARW support; you have my sympathy, it does sound really complicated. In fact, it casts doubt on Sony's approach to getting into the serious amateur and semi-professional market: their own software is not so good that they don't need other people making tools for their DSLRs, which are surprisingly good.
Of course, for my part, you could simplify the task by just doing the A100 formats...
Thanks again, I couldn't be without ExifTool - regards, Arthur.